Hi MervinSanchez,
Thank you for writing to Microsoft Community Forums.
We have checked this issue for you. The base language cannot be changed in Windows 10 once the selection of the language and installation is complete. To change the language the Windows 10 is installed in, would require a Custom Reinstallation of Windows 10.
I suggest you to follow this thread article on How to: Perform a Custom Installation of Windows, from Andre Da Costa Created on January 17, 2017. Check if that helps.
Disclaimer: While performing custom installation all your data and files will be saved in Windows.old folder, but all your installed application will be wiped out from your PC.
Hope it helps.
Regards,